J. Timmer

Diffraction dissociation in proton-proton collisions at ISR energies

Data are presented on the reaction pp → pX in the range of four-momentum transfer squared 0.04 0.01. The total diffractive cross section integrated over t and M2/s up to M2/s=0.05 rises by approximately 15% from σdif=6.5±0.2 mb at 550 GeV2 to σdif=7.5±0.3 mb at 3880 GeV2.

A study of the reaction p + p → p + p + X at ISR energies

Abstract We have performed an experiment to investigate the reaction p + p → p 1 + p 2 + X at the CERN Intersecting Storage Rings (ISR). The dependence of the cross-section on the mass and rapidity of the system X, and on the momentum transfer squared t 1 , t 2 to the outgoing protons is studied. We observe signals for the production of ϱ , ω , f, and A 2 mesons in the missing-mass spectra, and conclusions are made about the contribution of double-Pomeron exchange.

Search for new long-lived particles with masses in the range 1.4 to 3.0 GeV, at the CERN ISR

Abstract A search has been made at the CERN ISR for long-lived non-annihilating particles of two types: those which exhibit strong interactions and those which do not (heavy leptons). Invariant cross section upper limits of 6 nb GeV −2 and 1.8 nb GeV −2 were measured for these two classes of particles, respectively, for particle masses close to the antideuteron mass. Upper limits are also placed on the production of new particles with masses in the range 1.4 to 3.0 GeV, and invariant cross sections are quoted for π − , p , d production. The experiment was performed at √ s = 53 GeV with x (= 2 p L /√ s ) in the range 0.07 to 0.15 and p T between 0.08 and 0.16 GeV/ c . Antideuterons were identified by annihilation in a 1.4 m 3 scintillation calorimeter.